Method for adjusting laser radar, laser device and laser radar

ABSTRACT

A laser device is capable of coaxially outputting visible light and invisible light. The laser device includes a seed source outputting the invisible light, a visible light source outputting the visible light, a first wavelength division multiplexing module and N amplification modules, N is a positive integer. The seed source outputs pulsed laser to the amplification modules. The amplification modules perform power amplification on a signal passing therethrough to obtain a signal with power amplified. The first wavelength division multiplexing module performs wavelength division multiplexing processing on the visible light and the invisible light to ensure that an output end of the laser device is capable of coaxially outputting the visible light and the invisible light.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure is a continuation of International ApplicationNo. PCT/CN2021/142665, filed on Dec. 29, 2021, titled “method foradjusting laser radar, laser device, laser radar and applicationthereof”, the contents of which are incorporated herein by reference.

TECHNICAL FIELD

The present disclosure relates to the technical field of laserinstruments, and in particularly, relates to a method for adjustinglaser radar, a laser device and a laser radar.

BACKGROUND

Optical fiber laser devices have outstanding advantages, such as smallvolume, high efficiency, good beam quality and convenient thermalmanagement, and thus they are developing extremely rapidly and have beenwidely used in industry and national defense and other fields andexhibited a great prospect for development. For example, laser radarmade of an optical fiber laser device has been widely used in automaticdriving, mapping, robot navigation, space modeling and other scenes.

For laser radar, optical path adjusting is necessary before leaving thefactory, so as to ensure parameters such as azimuth and divergenceangles of the laser emitted. Because the light emitted by laser radar isgenerally invisible light, invisible light cameras (such as shortinfrared cameras) are usually used in the industry currently foradjusting, such as angle adjustment or the like, but the price ofinvisible light cameras is high, which is not conducive to reducingproduction cost for enterprises.

SUMMARY

An embodiment of the present disclosure provides a method for adjustinga laser radar, the laser radar includes a laser device and a collimationlens, the laser device is capable of coaxially outputting visible lightand invisible light, and the method includes:

-   -   providing a laser collimator and a target surface, and setting a        second distance according to wavelength of a invisible light of        the laser device, the second distance being a distance between a        lens of the laser collimator and the target surface;    -   obtaining a test deviation value about the second distance        according to the wavelength of the invisible light and the        wavelength of the visible light of the laser device;    -   adjusting the second distance according to the test deviation        value to obtain a corrected second distance; and    -   making the laser device output the visible light according to        the corrected second distance, and adjusting a first distance        until the area of a spot of the visible light on the target        surface reaches a minimum value, thereby completing the        adjusting for the laser radar, the first distance being a        distance between the laser device and the collimation lens.

Another embodiment of the present disclosure provides a laser device,the laser device is capable of coaxially outputting visible light andinvisible light, the laser device includes a seed source configured tooutput the invisible light, a visible light source configured to outputthe visible light, a first wavelength division multiplexing module and Namplification modules, N being a positive integer; wherein

-   -   the seed source is configured to output pulsed laser to the        amplification modules;    -   the amplification modules are configured to perform power        amplification on a signal passing therethrough to obtain a        signal with power amplified;    -   the first wavelength division multiplexing module is configured        to perform wavelength division multiplexing processing on the        visible light and the invisible light to ensure that an output        end of the laser device is capable of coaxially outputting the        visible light and the invisible light.

Still another embodiment of the present disclosure provides a laserradar. The laser radar includes a collimation lens and theabove-mentioned laser device. Light emitted by the laser device isprojected onto the collimation lens.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to explain specific embodiments of the present disclosure ortechnical solutions in the prior art more clearly, attached drawingsrequired in the description of the specific embodiments or the prior artwill be briefly introduced hereinafter; obviously, the attached drawingsin the following description are some embodiments of the presentdisclosure, and other attached drawings can be obtained according tothese attached drawings without creative labor for those of ordinaryskill in the art.

FIG. 1 is a schematic view of a method for adjusting laser radarprovided according to an embodiment of the present disclosure;

FIG. 2 is a schematic view of a laser device provided according to thepresent disclosure;

FIG. 3 is a schematic view of the laser device shown in FIG. 2 in afirst embodiment;

FIG. 4 is a schematic view of the laser device shown in FIG. 2 in asecond embodiment;

FIG. 5 is a schematic view of the laser device shown in FIG. 2 in athird embodiment;

FIG. 6 is a schematic view of the laser device shown in FIG. 2 in afourth embodiment;

FIG. 7 is a schematic view of the laser device shown in FIG. 2 in afifth embodiment;

FIG. 8 is a schematic view of a first amplification module in the laserdevice shown in FIG. 2 ;

FIG. 9 is a schematic view of the first amplification module shown inFIG. 8 in another embodiment;

FIG. 10 is a schematic view of the first amplification module shown inFIG. 8 in yet another embodiment;

FIG. 11 is a schematic view of the laser device shown in FIG. 2including an isolation filtering module;

FIG. 12 is a schematic view of the isolation filtering module shown inFIG. 11 ;

FIG. 13 is a schematic view of any amplification module except for thefirst amplification module in the laser device shown in FIG. 2 ;

FIG. 14 is a schematic view of the amplification module shown in FIG. 13in another embodiment;

FIG. 15 is a schematic view of any amplification module except for thefirst amplification module in the laser device shown in FIG. 2 inanother embodiment;

FIG. 16 is a schematic view of a laser radar in Embodiment 1;

FIG. 17 is a schematic view of a laser radar in Embodiment 2; and

FIG. 18 is a schematic view of a laser radar in Embodiment 3.

DETAILED DESCRIPTION

Hereinafter, embodiments of the present disclosure will be described indetail, examples of which are illustrated in the accompanying drawings,wherein the same or similar reference numerals indicate the same orsimilar elements or elements having the same or similar functionsthroughout the description. The embodiments described below withreference to the attached drawings are exemplary, and these embodimentsare only used for explaining the present disclosure, and should not beconstrued as limiting the present disclosure.

In the description of the present disclosure, it shall be appreciatedthat, orientations or positional relationships indicated by terms suchas “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”,“top”, “bottom”, “front”, “back”, “left”, “right”, “vertical”,“horizontal”, “top”, “bottom”, “inner”, “outer”, “clockwise”,“anticlockwise”, “axial direction”, “radial direction”, “circumferentialdirection” or the like are orientations or positional relationshipsshown based on the attached drawings; these terms are only used for theconvenience of describing the present disclosure and simplifying thedescription, and do not indicate or imply that the referred devices orelements must have specific orientations, be constructed and operated inspecific orientations, and thus these terms should not be construed aslimiting the present disclosure.

In addition, the terms “first” and “second” are only used for thedescriptive purpose, and should not be construed as indicating orimplying relative importance or implicitly indicating the number ofindicated technical features. Therefore, the features defined by “first”and “second” may include one or more of the features explicitly orimplicitly. In the description of the present disclosure, “plural” meanstwo or more, unless otherwise specifically defined.

In the present disclosure, unless otherwise specified and defined, termssuch as “installation”, “linkage”, “connection” and “fixation” should bebroadly understood; for example, elements may be fixedly connected, ordetachably connected or formed integrally; elements may be mechanicallyconnected or electrically connected; elements may be directly connected,or indirectly connected through an intervening medium, and theconnection may be the internal communication of two elements or theinteraction between two elements. For those of ordinary skill in theart, the specific meanings of the above terms in the present disclosuremay be understood according to specific situations.

In the present disclosure, unless otherwise specified and defined, afirst feature being located “above” or “below” a second feature mayrefer to that the first feature is in direct contact with the secondfeature, or the first feature is in indirect contact with the secondfeature through an intervening medium. Moreover, the first feature beinglocated “on”, “above” and “on top of” the second feature may mean thatthe first feature is directly above or obliquely above the secondfeature, or just mean that the level of the first feature is higher thanthe level of the second feature. The first feature being located“under”, “below” and “beneath” the second feature may mean that thefirst feature is directly below or obliquely below the second feature,or just mean that the level of the first feature is lower than the levelof the second feature.

As shown in FIG. 1 , the present disclosure provides a method foradjusting laser radar, which is configured to perform adjusting on alaser radar 200, and the laser radar 200 includes a laser device 100 anda collimation lens 201. The laser device 100 has the characteristic ofcoaxially outputting visible light and invisible light. The collimationlens 201 is arranged in front of the output end of the laser device 100.A distance between the laser device 100 and the collimation lens 201 isdefined as a first distance. The method for adjusting laser radarincludes the following steps:

Step 1: providing a laser collimator 301 and a target surface 302.

The laser collimator 301 is arranged on one side of the collimation lens201 far away from the laser device 100. The target surface 302 isarranged on one side of the laser collimator 301 far away from thecollimation lens 201.

The distance between the laser collimator 301 and the target surface 302is set according to the wavelength of invisible light in the laserdevice 100, and the distance between the laser collimator 301 and thetarget surface 302 at this point is defined as a second distance.

Step 2: obtaining a test deviation value about the second distanceaccording to the wavelength of the invisible light and the wavelength ofthe visible light of the laser device 100.

Specifically, the test deviation value is obtained by performing thefollowing sub-steps in a simulation system:

-   -   positioning the laser radar 200, the laser collimator 301 and        the target surface 302 according to adjustment positions;    -   setting the first distance and the second distance according to        the wavelength of the invisible light of the laser radar 200;    -   making the laser radar 200 output visible light, and observing        the spot of the visible light on the target surface 302;    -   keeping the first distance unchanged, moving the target surface        302, and continuing observing the variation of the spot of the        visible light on the target surface 302;    -   recording a variation amount of movement of the target surface        302 if the area of the spot of the visible light on the target        surface 302 reaches the minimum value, wherein the variation        amount is the test deviation value of the second distance.

The deviation value in the simulation system reflects the change of thesecond distance caused by the change of a single variable (switchingbetween visible light and invisible light) when the first distanceremains unchanged. While in the real system, the visible light and theinvisible light are output coaxially, and the same set of lasercollimator and target surface are used, so the change of single variablecan also be realized, and the deviation value of the simulation systemcan be used in the real system. However, the actual system is notperfect, and some deviation is inevitable, and thus it is necessary toadjust the first distance, i.e., fine-adjust the first distance, suchthat the final adjustment in the actual system is achieving.

Step 3: adjusting the second distance according to the test deviationvalue to obtain a corrected second distance.

Step 4: making the laser device 100 output the visible light accordingto the corrected second distance, and adjusting a first distance untilthe area of a spot of the visible light on the target surface 302reaches a minimum value. That is, the adjusting for the laser radar 200is thereby completed.

The method for adjusting laser radar provided according to the presentdisclosure may also verify the adjusted laser radar 200. The specificverification steps are as follows:

-   -   taking out a standard laser radar 200 (i.e., a laser radar 200        with correct optical path) and making the standard laser radar        200 output visible light;    -   making a distance between the laser collimator 301 and the        target surface 302 be the corrected second distance, wherein the        corrected second distance is the distance used by the adjusted        laser radar 200 in adjusting;    -   performing the following judgment on the spot of the visible        light on the target surface 302:    -   determining that the original laser radar 200 that was adjusted        has indeed completed the adjusting of the optical path if the        area of the spot of the visible light on the target surface 302        reaches the minimum value; otherwise, determining that the        adjusting is wrong.

The standard laser radar 200 may be a laser radar adjusted by aninvisible light camera or other means.

According to the method for adjusting laser radar provided by thepresent disclosure, since the laser device 100 has the characteristic ofcoaxially outputting visible light and invisible light, the invisiblelight in the laser radar 200 can be adjusted by observing the visiblelight, which is convenient for adjusting the laser radar 200; and arelatively cheap common camera may be used for adjusting, which reducesthe adjusting cost and facilitates the production operation and thereduction of production cost of enterprises.

As shown in FIG. 2 , the present disclosure further provides a laserdevice 100, which is applied to the laser radar 200 of the method foradjusting laser radar described above. The laser device 100 has thecharacteristic of coaxially outputting visible light and invisiblelight. The laser device 100 includes a seed source 10 that outputsinvisible light, a visible light source 20 that outputs visible light, afirst wavelength division multiplexing module 30 and an amplificationmodule 40.

The seed source 10 is configured to output pulsed laser and transmit thepulsed laser to the amplification module 40 for amplification.

The first wavelength division multiplexing module 30 is configured toperform wavelength division multiplexing processing on the visible lightoutput by the visible light source 20 and the invisible light output bythe seed source 10, so as to ensure that an output end of the laserdevice 100 has the characteristic of coaxially outputting the visiblelight and the invisible light.

There are N amplification modules 40, wherein N is a positive integer.The amplification module 40 is configured to perform power amplificationon a signal passing therethrough to obtain a signal with poweramplified.

The laser device 100 performs wavelength division multiplexingprocessing on visible light and invisible light through the firstwavelength division multiplexing module 30, such that the output end ofthe laser device 100 has the characteristic of coaxially outputtingvisible light and invisible light, and thus the invisible light in thelaser radar 200 using the laser device 100 can be adjusted by observingthe visible light, which is convenient for adjusting of the laser radar200; and a relatively cheap common camera may be used for adjusting,which reduces the adjusting cost and facilitates the productionoperation and the reduction of production cost of enterprises.

Specifically, when N=1, the laser device 100 has the following twoembodiments.

As shown in FIG. 3 , in a first embodiment, an output end of the seedsource 10 is connected with a first input end of the first wavelengthdivision multiplexing module 30. An output end of the visible lightsource 20 is connected with a second input end of the first wavelengthdivision multiplexing module 30. An output end of the first wavelengthdivision multiplexing module 30 is connected with an input end of theamplification module 40. An output end of the amplification module 40serves as the output end of the laser device 100. The laser device 100outputs through optical fibers.

As shown in FIG. 4 , in a second embodiment, the output end of the seedsource 10 is connected with the input end of the amplification module40. The output end of the amplification module 40 is connected with thefirst input end of the first wavelength division multiplexing module 30.The output end of the visible light source 20 is connected with thesecond input end of the first wavelength division multiplexing module30. The output end of the first wavelength division multiplexing module30 serves as the output end of the laser device 100, and the laserdevice 100 outputs through optical fibers.

When N≠1, the N amplification modules 40 are defined as a firstamplification module 41 to a Nth amplification module 4N in sequence.The laser device 100 has the following embodiments.

As shown in FIG. 5 , in a third embodiment, the output end of the seedsource 10 is connected with the input end of the first amplificationmodule 41. The N amplification modules 40 are connected in sequence torealize step-by-step power amplification of the signal. An output end ofthe Nth amplification module 4N is connected with the first input end ofthe first wavelength division multiplexing module 30. The output end ofthe visible light source 20 is connected with the second input end ofthe first wavelength division multiplexing module 30. The output end ofthe first wavelength division multiplexing module 30 serves as theoutput end of the laser device 100, and the laser device 100 outputsthrough optical fibers.

As shown in FIG. 6 , in a fourth embodiment, the output end of the seedsource 10 is connected with the first input end of the first wavelengthdivision multiplexing module 30. The output end of the visible lightsource 20 is connected with the second input end of the first wavelengthdivision multiplexing module 30. The output end of the first wavelengthdivision multiplexing module 30 is connected with the input end of thefirst amplification module 41. The N amplification modules 40 areconnected in sequence to realize step-by-step power amplification of thesignal. The output end of the Nth amplification module 4N serves as theoutput end of the laser device 100, and the laser device 100 outputsthrough optical fibers.

As shown in FIG. 7 , in a fifth embodiment, M is defined as a positiveinteger and the value range of M is restricted by the followingrelationship: M∈[1, N−1]. The Mth amplification module is 4M, and the(M+1)th amplification module is 4(M+1).

The output end of the seed source 10 is connected with the input end ofthe first amplification module 41. An output end of the Mthamplification module 4M is connected with the first input end of thefirst wavelength division multiplexing module 30. The output end of thevisible light source 20 is connected with the second input end of thefirst wavelength division multiplexing module 30. The output end of thefirst wavelength division multiplexing module 30 is connected with aninput end of the (M+1)th amplification module 4(M+1). The output end ofthe Nth amplification module 4N serves as the output end of the laserdevice 100, and the laser device 100 outputs through optical fibers. TheN amplification modules 40 are connected in sequence to realizestep-by-step power amplification of the signal.

As shown in FIG. 8 , the first amplification modules 40 among the Namplification modules 40 is defined as the first amplification module 41in each of the first to fifth embodiments, and the first amplificationmodule 41 includes a first pumping source 411, a first coupling module412 and a first gain optical fiber 413.

The first pumping source 411 is configured to emit first pump light.

A first end of the first coupling module 412 serves as the input end ofthe first amplification module 41, a second end of the first couplingmodule 412 is connected with an output end of the first pumping source411, and a third end of the first coupling module 412 is connected witha first end of the first gain optical fiber 413.

The first gain optical fiber 413 is configured to perform poweramplification on the signal passing therethrough, and a second end ofthe first gain optical fiber 413 serves as the output end of the firstamplification module 41.

As shown in FIG. 9 , in another embodiment, the first amplificationmodule 41 further includes a reflector 414.

The reflector 414 is connected with the second end of the first gainoptical fiber 413, and is configured to reflect pulsed laser output bythe first gain optical fiber 413 after first power amplification back tothe first gain optical fiber 413, such that the first gain optical fiber413 performs second power amplification on the signal after the firstpower amplification.

In another embodiment, the first amplification module 41 furtherincludes a circulator 415.

A first port of the circulator 415 serves as the input end of the firstamplification module 41, a second port of the circulator 415 isconnected with the first end of the first coupling module 412, and athird port of the circulator 415 serves as the output end of the firstamplification module 41.

As shown in FIG. 10 , in yet another embodiment, the first amplificationmodule 41 further includes a first heat dissipation unit 416, and thefirst heat dissipation unit 416 is configured to perform coolingprocessing on the first pumping source 411.

As shown in FIG. 11 , if N≠1, then the laser device 100 further includesan isolation filtering module 50. The isolation filtering module 50 isarranged between two amplification modules 40, so as to prevent signalbackflow and filter noise.

The number of isolation filtering modules 50 is P, and P is a positiveinteger, and the value range of P is restricted by the followingrelationship: P∈[1, N−1].

As shown in FIG. 12 , in some embodiments, the isolation filteringmodule 50 includes an isolator 51 and a filter 52.

In the first to fourth embodiments, an input end of the isolator 51serves as an input end of the isolation filtering module 50. An outputend of the isolator 51 is connected with an input end of the filter 52.An output end of the filter 52 serves as an output end of the isolationfiltering module 50.

Please refer to FIG. 7 and FIG. 18 , in the fifth embodiment, theisolation filtering module 50 arranged between the Mth amplificationmodule 4M and the (M+1)th amplification module 4(M+1) has a connectionrelationship different from that of the isolation filtering module 50shown in FIG. 12 .

Specifically, the input end of the filter 52 serves as the input end ofthe isolation filtering module 50. The output end of the Mthamplification module 4M is connected with the input end of the filter52. The output end of the filter 52 is connected with the first inputend of the first wavelength division multiplexing module 30. The outputend of the visible light source 20 is connected with the second inputend of the first wavelength division multiplexing module 30. The outputend of the first wavelength division multiplexing module 30 is connectedwith the input end of the isolator 51. The output end of the isolator 51serves as the output end of the isolation filtering module 50. Theoutput end of the isolator 51 is connected with the input end of the(M+1)th amplification module 4(M+1).

The isolation filtering module 50 arranged between the other twoamplification modules 40 may be the same as that shown in FIG. 12 .

As shown in FIG. 13 , in some embodiments, if N≠1, then the Qthamplification module 4Q is defined as any amplification module 40 amongthe N amplification modules 40 except for the first amplification module41. Q is a positive integer, and the value range of Q is restricted bythe following relationship: Q∈[2, N].

The Qth amplification module 4Q includes a Qth pumping source 4Q1, a Qthgain optical fiber 4Q2 and a Qth beam combiner 4Q3.

The Qth pumping source 4Q1 is configured to emit a Qth pump light.

An input end of the Qth gain optical fiber 4Q2 serves as the input endof the Qth amplification module 4Q. An output end of the Qth gainoptical fiber 4Q2 is connected with a first input end of the Qth beamcombiner 4Q3.

A second input end of the Qth beam combiner 4Q3 is connected with anoutput end of the Qth pumping source 4Q1, and an output end of the Qthbeam combiner 4Q3 serves as an output end of the Qth amplificationmodule 4Q.

The Qth pump light and a signal output by the Qth gain optical fiber 4Q2are incident on the Qth beam combiner 4Q3 in opposite directions.

As shown in FIG. 14 , in some embodiments, the Qth amplification module4Q further includes a Qth heat dissipation unit 4Q4, and the Qth heatdissipation unit 4Q4 is configured to perform cooling processing on theQth pumping source 4Q1.

As shown in FIG. 15 , in some other embodiments, if N>2, then the Qthamplification module 4Q is defined as any amplification module 40 amongthe N amplification modules 40 except for the first amplification module41. Q is a positive integer, and the value range of Q is restricted bythe following relationship: Q∈[2, N].

The laser device 100 further includes pumping sources 60 and beamsplitters 70. The pumping sources 60 are connected with the beamsplitters 70 in one-to-one correspondence.

The numbers of the pumping sources 60 and the beam splitters 70 are O,and O is a positive integer, and the value range of O is restricted bythe following relationship: O∈[1, N−2].

The pumping sources 60 simultaneously supply energy to R amplificationmodules 40 except for the first amplification module 41 according to abeam splitting ratio, and the O pumping sources 60 complete the energysupply to N−1 amplification modules 40 except for the firstamplification module 41. R is defined as a positive integer, and thevalue range of R is restricted by the following relationship: R∈[2,N−1].

The Qth amplification module 4Q includes a Qth gain optical fiber 4Q2and a Qth beam combiner 4Q3.

An input end of the Qth gain optical fiber 4Q2 serves as the input endof the Qth amplification module 4Q. An output end of the Qth gainoptical fiber 4Q2 is connected with a first input end of the Qth beamcombiner 4Q3.

A second input end of the Qth beam combiner 4Q3 is connected with anoutput end of the beam splitter 70, and an output end of the Qth beamcombiner 4Q3 serves as the output end of the Qth amplification module4Q.

A signal output by the beam splitter 70 and a signal output by the Qthgain optical fiber 4Q2 are incident on the Qth beam combiner 4Q3 inopposite directions.

In some embodiments, if N=3, then the beam splitting ratio of thepumping source 60 ranges from 3:17 to 7:13.

The present disclosure further provides a laser radar 200, the laserradar 200 includes a collimator device 201 and the laser device 100 inany of the above embodiments, and the laser device 100 has thecharacteristic of coaxially outputting visible light and invisiblelight. The light emitted by the laser device 100 is projected onto thecollimator device 201.

The laser device 100 adopted by the laser radar 200 performs wavelengthdivision multiplexing processing on visible light and invisible lightthrough the first wavelength division multiplexing module 30, such thatthe output end of the laser device 100 has the characteristic ofcoaxially outputting visible light and invisible light, and thus theinvisible light in the laser radar 200 can be adjusted by observing thevisible light, which is convenient for adjustment of the laser radar200; and a relatively cheap common camera may be used for adjusting,which reduces the adjusting cost and facilitates the productionoperation and the reduction of production cost of enterprises.

The present disclosure further provides a motor vehicle including thelaser radar 200 described above.

The present disclosure further provides a robot including the laserradar 200 described above.

Specifically, reference may be made to the following embodiments.

Embodiment 1

Referring to FIG. 16 , the Embodiment 1 of the present disclosureprovides a laser radar 200. The laser radar 200 can coaxially outputvisible and invisible lasers.

The laser radar 200 includes a seed source 10, a visible light source20, a first wavelength division multiplexing module 30, a firstamplification module 41, an isolation filtering module 50, a secondamplification module 42 and a collimation lens 201.

In this embodiment, the connection mode of the laser device 100 is thesame as that in the fourth embodiment.

The seed source 10, the visible light source 20, the first wavelengthdivision multiplexing module 30, the first amplification module 41, theisolation filtering module 50, the second amplification module 42 andthe collimation lens 201 are connected through optical fibers.

The seed source 10 is any of infrared laser sources with wavelengths of1550 nm, 1064 nm, 2000 nm and 1310 nm. The seed source 10 emits pulsedlight with a peak power of about 10 mW through circuit modulation.

The visible light source 20 is a pigtail laser device with a wavelengthof 650 nm or 532 nm. The visible light source 20 emits light with anaverage power of 5 mW to 10 mW through circuit modulation.

The first wavelength division multiplexing module 30 adopts a wavelengthdivision multiplexer.

The first amplification module 41 performs primary amplification on thelight passing therethrough by forward pumping. The first amplificationmodule 41 includes a first pumping source 411, a first coupling module412, a first gain optical fiber 413, a reflector 414 and a circulator415.

The first pumping source 411 is a 976 nm single-mode pump.

The first gain optical fiber 413 is an erbium-doped optical fiber.

The reflector 414 is a reflecting mirror or a high reflection grating.

The circulator 415 is a three-port circulator.

The light amplified twice by the first amplification module 41 is outputfrom the third port of the circulator 415, and the output power is onthe order of about 10 mW.

The isolation filtering module 50 is used for protecting and filteringamplified spontaneous emission (ASE) light brought by the primaryamplification. The isolation filtering module 50 includes an isolator 51and a filter 52. The isolator 51 can protect the seed source 10 fromdamaging by the light backflow.

The second amplification module 42 performs secondary amplification onthe light passing therethrough by reverse pumping. The secondamplification module 42 includes a second pumping source 421, a secondgain optical fiber 422 and a second beam combiner 423.

The second pumping source 421 is a 940 nm multi-mode pump.

The second gain optical fiber 422 is an erbium-ytterbium co-dopedoptical fiber.

The power of the light amplified by the second amplification module 42can reach 1 W to 2 W.

Specifically, the output end of the seed source 10 is connected with thefirst input end of the first wavelength division multiplexing module 30.The output end of the visible light source 20 is connected with thesecond input end of the first wavelength division multiplexing module30. The output end of the first wavelength division multiplexing module30 is connected with the first port of the circulator 415.

The second port of the circulator 415 is connected with the first end ofthe first coupling module 412. The second end of the first couplingmodule 412 is connected with the output end of the first pumping source411, and the third end of the first coupling module 412 is connectedwith the first end of the first gain optical fiber 413. The second endof the first gain optical fiber 413 is connected with the reflector 414.The third port of the circulator 415 serves as the output end of thefirst amplification module 41.

The third port of the circulator 415 is connected with the input end ofthe isolator 51. The output end of the isolator 51 is connected with theinput end of the filter 52. The output end of the filter 52 serves asthe output end of the isolation filtering module 50.

The output end of the filter 52 is connected with the input end of thesecond gain optical fiber 422. An output end of the second gain opticalfiber 422 is connected with a first input end of the second beamcombiner 423. A second input end of the second beam combiner 423 isconnected with an output end of the second pumping source 421. An outputend of the second beam combiner 423 serves as the output end of thesecond amplification module 42, and is connected with the collimationlens 201.

Embodiment 2

Referring to FIG. 17 , the Embodiment 2 provides a laser radar 200. TheEmbodiment 2 differs from the Embodiment 1 described above in that:

-   -   in this embodiment, the connection mode of the laser device 100        adopts the connection mode in the third embodiment.

Embodiment 3

Referring to FIG. 18 , a laser radar 200 provided by the Embodiment 3differs from the Embodiment 1 and the Embodiment 2 described above inthat:

-   -   in this embodiment, the connection mode of the laser device 100        adopts the connection mode in the fifth embodiment.

Moreover, in this embodiment, the isolator 51 and the filter 52 of theisolation filtering module 50 are arranged in different positions fromthose in other embodiments.

Specifically, in this embodiment, the filter 52 is arranged between thefirst amplification module 41 and the first wavelength divisionmultiplexing module 30. The isolator 51 is positioned between the firstwavelength division multiplexing module 30 and the second amplificationmodule 42.

The isolator 51 is used to prevent light backflow, the filter 52 willcause some stray light, and thus, the isolator 51 is usually placed infront of the filter 52, such that the stray light generated by thefilter 52 will not cross to the front end of the isolator 51.

In this embodiment, by placing the filter 52 in front of the isolator51, the purity of the invisible light for coupling with the visiblelight passing through the filter 52 is improved (the signal-to-noiseratio is higher) after the primary amplification, such that theinvisible light can be better coupled with the visible light and improvethe quality of the signal coupled.

In the description of this specification, descriptions made withreference to terms “one embodiment”, “some embodiments”, “examples”,“specific examples” or “some examples” mean that specific features,structures, materials or characteristics described in connection withthe embodiment or example are included in at least one embodiment orexample of the present disclosure. In this specification, the schematicexpressions of the above terms are not necessarily aimed at the sameembodiment or example. Moreover, the specific features, structures,materials or characteristics described may be combined in any one ormore embodiments or examples in a suitable manner. In addition, thoseskilled in the art can incorporate and combine different embodiments orexamples and features of different embodiments or examples described inthis specification without mutual contradiction.

Although the embodiments of the present disclosure have been shown anddescribed above, it shall be appreciated that, the above embodiments areexemplary and should not be construed as limitations of the presentdisclosure, and those of ordinary skill in the art can make changes,modifications, substitutions and variations to the above embodimentswithin the scope of the present disclosure.

What is claimed is:
 1. A method for adjusting a laser radar, the laserradar comprising a laser device and a collimation lens, the laser devicecapable of coaxially outputting visible light and invisible light, andthe method comprising: providing a laser collimator and a targetsurface, and setting a second distance according to wavelength of ainvisible light of the laser device, the second distance being adistance between a lens of the laser collimator and the target surface;obtaining a test deviation value about the second distance according tothe wavelength of the invisible light and the wavelength of the visiblelight of the laser device; adjusting the second distance according tothe test deviation value to obtain a corrected second distance; andmaking the laser device output the visible light according to thecorrected second distance, and adjusting a first distance until the areaof a spot of the visible light on the target surface reaches a minimumvalue, thereby completing the adjusting for the laser radar, the firstdistance being a distance between the laser device and the collimationlens.
 2. The method of claim 1, further comprising: taking out astandard laser radar and making the standard laser radar output visiblelight; making a distance between the laser collimator and the targetsurface be the corrected second distance; and determining that thestandard laser radar has been adjusted if the area of the spot of thevisible light on the target surface reaches the minimum value.
 3. Themethod of claim 1, wherein the obtaining a test deviation value aboutthe second distance according to the wavelength of the invisible lightand the wavelength of the visible light of the laser device comprises:setting the first distance and the second distance according to thewavelength of the invisible light of the laser radar in a simulationsystem; making the laser radar output the visible light, and observingthe spot of the visible light on the target surface; keeping the firstdistance unchanged, moving the target surface, and continuing to observethe variation of the spot of the visible light on the target surface;and recording a variation amount of movement of the target surface ifthe area of the spot of the visible light on the target surface reachesthe minimum value, the variation amount being defined as the testdeviation value of the second distance.
 4. A laser device, capable ofcoaxially outputting visible light and invisible light, the laser devicecomprising a seed source configured to output the invisible light, avisible light source configured to output the visible light, a firstwavelength division multiplexing module and N amplification modules, Nbeing a positive integer; wherein the seed source is configured tooutput pulsed laser to the amplification modules; the amplificationmodules are configured to perform power amplification on a signalpassing therethrough to obtain a signal with power amplified; the firstwavelength division multiplexing module is configured to performwavelength division multiplexing processing on the visible light and theinvisible light to ensure that an output end of the laser device iscapable of coaxially outputting the visible light and the invisiblelight.
 5. The laser device of claim 4, wherein N=1, the amplificationmodule is defined as a first amplification module; an output end of theseed source is connected with a first input end of the first wavelengthdivision multiplexing module; an output end of the visible light sourceis connected with a second input end of the first wavelength divisionmultiplexing module; an output end of the first wavelength divisionmultiplexing module is connected with an input end of the amplificationmodule; an output end of the amplification module serves as the outputend of the laser device, and the laser device outputs through opticalfibers.
 6. The laser device of claim 4, wherein N=1, the amplificationmodule is defined as a first amplification module; an output end of theseed source is connected with an input end of the amplification module;an output end of the amplification module is connected with a firstinput end of the first wavelength division multiplexing module; anoutput end of the visible light source is connected with a second inputend of the first wavelength division multiplexing module; an output endof the first wavelength division multiplexing module serves as theoutput end of the laser device, and the laser device outputs throughoptical fibers.
 7. The laser device of claim 4, wherein N≠1, the Namplification modules are defined as a first amplification module to anNth amplification module in sequence; an output end of the seed sourceis connected with an input end of the first amplification module; the Namplification modules are connected in sequence for realizingstep-by-step power amplification of the signal; an output end of the Nthamplification module is connected with a first input end of the firstwavelength division multiplexing module; an output end of the visiblelight source is connected with a second input end of the firstwavelength division multiplexing module; an output end of the firstwavelength division multiplexing module serves as the output end of thelaser device, and the laser device outputs through optical fibers. 8.The laser device of claim 4, wherein NA the N amplification modules aredefined as a first amplification module to an Nth amplification modulein sequence; an output end of the seed source is connected with a firstinput end of the first wavelength division multiplexing module; anoutput end of the visible light source is connected with a second inputend of the first wavelength division multiplexing module; an output endof the first wavelength division multiplexing module is connected withan input end of the first amplification module; the N amplificationmodules are connected in sequence for realizing step-by-step poweramplification of the signal; an output end of the Nth amplificationmodule serves as the output end of the laser device, and the laserdevice outputs through optical fibers.
 9. The laser device of claim 4,wherein NA M is defined as a positive integer and a value range of M isrestricted by the following relationship: M∈[1, N−1]; the Namplification modules are defined as a first amplification module to anNth amplification module in sequence; an output end of the seed sourceis connected with an input end of the first amplification module; the Namplification modules are connected in sequence for realizingstep-by-step power amplification of the signal; an output end of an Mthamplification module is connected with a first input end of the firstwavelength division multiplexing module; an output end of the visiblelight source is connected with a second input end of the firstwavelength division multiplexing module; an output end of the firstwavelength division multiplexing module is connected with an input endof an (M+1)th amplification module; an output end of the Nthamplification module serves as the output end of the laser device, andthe laser device outputs through optical fibers.
 10. The laser device ofclaim 7, wherein N≠1, the laser device further comprises P isolationfiltering modules, and the isolation filtering modules are arrangedbetween two of the amplification modules for preventing signal backflowand filtering noise; P is a positive integer and a value range of P isrestricted by the following relationship: P∈[1, N−1].
 11. The laserdevice of claim 10, wherein the isolation filtering module comprises anisolator and a filter, an input end of the isolator serves as an inputend of the isolation filtering module; an output end of the isolator isconnected with an input end of the filter; an output end of the filterserves as an output end of the isolation filtering module.
 12. The laserdevice of claim 9, wherein N≠1, the laser device further comprises anisolator and a filter, the output end of the Mth amplification module isconnected with an input end of the filter; an output end of the filteris connected with the first input end of the first wavelength divisionmultiplexing module; the output end of the first wavelength divisionmultiplexing module is connected with an input end of the isolator; anoutput end of the isolator is connected with the input end of the(M+1)th amplification module.
 13. The laser device of claim 7, whereinN≠1, and a Qth amplification module is defined as any amplificationmodule among the N amplification modules except for the firstamplification module, and the Qth amplification module comprises: a Qthpumping source, configured to emit a Qth pump light; a Qth gain opticalfiber, an input end of the Qth gain optical fiber serving as an inputend of the Qth amplification module; a Qth beam combiner, a first inputend of the Qth beam combiner connected with an output end of the Qthgain optical fiber, a second input end of the Qth beam combinerconnected with an output end of the Qth pumping source, and an outputend of the Qth beam combiner serving as an output end of the Qthamplification module; wherein the Qth pump light and a signal output bythe Qth gain optical fiber are incident on the Qth beam combiner inopposite directions; Q is a positive integer and a value range of Q isrestricted by the following relationship: Q∈[2, N].
 14. The laser deviceof claim 13, wherein the Qth amplification module further comprises aQth heat dissipation unit configured to cool the Qth pumping source. 15.The laser device of claim 7, wherein N>2, O is defined as a positiveinteger and a value range of O is restricted by the followingrelationship: O∈[1, N−2]; R is defined as a positive integer and a valuerange of R is restricted by the following relationship: R∈[2, N−1]; Q isdefined as a positive integer and a value range of Q is restricted bythe following relationship: Q∈[2, N]; the laser device further comprisesO pumping sources and O beam splitters, the pumping sources areconnected with the beam splitters in one-to-one correspondence, thepumping sources are configured to simultaneously supply energy to Ramplification modules except for the first amplification moduleaccording to a beam splitting ratio, and the O pumping sources areconfigured to supply energy to N−1 amplification modules except for thefirst amplification module; the Qth amplification module is defined asany amplification module among the N amplification modules except forthe first amplification module, and the Qth amplification modulecomprises: a Qth gain optical fiber, an input end of the Qth gainoptical fiber serving as an input end of the Qth amplification module; aQth beam combiner, a first input end of the Qth beam combiner connectedwith an output end of the Qth gain optical fiber, a second input end ofthe Qth beam combiner connected with an output end of the beam splitter,and an output end of the Qth beam combiner serving as an output end ofthe Qth amplification module; wherein a signal output by the beamsplitter and a signal output by the Qth gain optical fiber are incidenton the Qth beam combiner in the opposite directions.
 16. The laserdevice of claim 15, wherein N=3, and the beam splitting ratio of thepumping source ranges from 3:17 to 7:13.
 17. The laser device of claim5, wherein the first amplification module comprises: a first pumpingsource, configured to emit a first pump light; a first coupling module,a first end of the first coupling module serving as an input end of thefirst amplification module, and a second end of the first couplingmodule being connected with an output end of the first pumping source; afirst gain optical fiber, configured to perform power amplification on asignal passing therethrough, a first end of the first gain optical fiberconnected with a third end of the first coupling module.
 18. The laserdevice of claim 17, wherein the first amplification module furthercomprises a reflector, the reflector is connected with a second end ofthe first gain optical fiber and is configured to reflect pulsed laseroutput by the first gain optical fiber after first power amplificationback to the first gain optical fiber, such that the first gain opticalfiber performs second power amplification on the signal after the firstpower amplification.
 19. The laser device of claim 18, wherein the firstamplification module further comprises a circulator, a first port of thecirculator serves as the input end of the first amplification module, asecond port of the circulator is connected with the first end of thefirst coupling module, and a third port of the circulator serves as anoutput end of the first amplification module.
 20. A laser radar,comprising a collimation lens and the laser device of claim 4, whereinlight emitted by the laser device is projected onto the collimationlens.